Polishing of glass plates



May 10, 1960 P. R. HEYMES 2,935,823

POLISHING OF GLASS PLATES Filed Aug. 9, 1956 4 Sheets-Sheet 1 IN VEN TOR.

PIERRE HEYMES F1 g- E BY I MM J ATTORiiEYS May 10, 1960 P. R. HEYMES POLISHING OF GLASS PLATES 4 Sheets-Sheet 2 Filed Aug. 9, 1956 w 0 o o o o o o o o o o o o o OOOOU go o o m OOOOOOOOOOO OOOOO OOOOO 60000000900 0OOOOOOOOOOOO OOE maul;

R s m m 7% M U VH.WT.. m E M R M m 6 A m y 1 1960 P. R. HEYMES 2,935,823

PLATE 4 Sheets Sheet 3 May 10, 1960 P. R. HEYMES 2,935,323

POLISHING OF GLASS PLATES Filed Aug. 9. 1956 4 Sheets-Sheet 4 95 INVENTOR.

PIERRE HEYMES ATTOR YS United States Patent O 2,935,823 POLISHING F GLASS PLATES Pierre Ren Heymes, Paris, France, assignor to Societe Anonyme des Manufactures des Glaces et Produits ghirniques de Saint-Gobain, Chauny 8: Cirey, Paris,

rance Application August 9, 1956, Serial No. 602,982 Claims priority, application France August 9, 1955 29 Claims. (Cl. 51-119) This invention relates to tools for polishing glass plates.

The polishing of glass plates is a special subject which has received great attention both as to methods and as to the machinery employed.

Generally speaking, the polishing tools are moved on the surface to be worked, and during the movement are subject to a certain amount of pressure while they are supplied with a liquid, which works either because of its own nature or because it carries an abrasive.

The polishing tools are generally faced with felt, and in most commercial installations the shape of the tool is circular, it being a disk one face of which is pressed against the glass while it is rotated. In such installations the tools are usually employed in gangs because that is necessary in order to achieve a good polishing.

Another type of tool is known which is sometimes called the long-bar type belonging to apparatus which is not rotary, thereby differing from the disks, but is moved with periodic translatory motion whereby each point of the surface of the tool moves in a circle of amplitude equal to that of every other point.

The invention relates more particularly to such polishing tools of this type serving for the continuous working of glass plates which are moved rectilinearly under the tool while this is given a periodic translating motion.

In such a case the tool extends over substantially the whole width of the glass plate in a direction transverse to the direction of movement of the plate. These tools are supplied with a polishing liquid under a certain pressure by channels passing through them and reaching the operative face of said tools.

Owing to the fact that, in this arrangement, the polishing tool covers a relatively important surface of the plate, an equal and regular distribution of the liquid to all glass contacting portion of the polishing tool is diificult.

It is an object of this invention to make improved polishing tools which are capable of working all parts of the surface engaged by the tool equally. In particular, it is an object of this invention, to improve the working surface of tools of the long-bar type, to which is given motion of a type which is adapted to produce isotropic working of the surface, for example, periodic, closed curve, translatory motion. Another object of the invention is to produce glass of improved surface characteristics, having fewer pits at the conclusion of polishing. Other objects of the invention will be in part apparent and in part set forth as the description proceeds.

The objects of the invention are accomplished generally speaking by forming the operative face of the polishing tool, which is to contact the surface to be worked with longitudinally extending grooves into which open channels supplying the polishing liquid in such a way that, if two adjacent grooves are considered, one at least is provided with inlet means for said liquid.

In one embodiment of the invention two kinds of grooves may alternate with one another on the operative face of the tool, namely grooves having a closed boundary and into which open channels supplying the liquid and non-fed grooves having outlet means. It is also a part of the invention that the fluid which is introduced into 2,935,823 Patented May 10, 1960 the closed groove is introduced with sulficient pressure to cause it to pass over the adjacent lands. The pressure may also be made sufficient to cause it to escape from those grooves or channels which have outlets, thus providing for a continuous and uniform flow of the said liquid to all parts of the face of the tool. There is thus provided a forced feeding of the lands which work the surface of the glass in such manner that the liquid is uniformly distributed to all parts of the working surface. A satisfactory method of construction is to alternate the channels of supply with the channels of discharge. In one form of the invention the channels of discharge or outlet are simply supplied with open ends, which provides for an endwise discharge of used liquid. In another form of the invention the channels of discharge are also surrounded by lands but are provided with discharge ports through the tool.

According to another embodiment of the invention, both grooves on either side of a working projection of the tool may be provided with orifices supplying liquid, the discharge being effected through one, or both grooves in such a way that the polishing liquid flows under the working projection as a consequence of the more or less high pressure of the liquid in both grooves bounding the rubbing projection.

As regards the arrangement of the grooves, it is advantag eous that the shape of the working projection bounded by the grooves, have a form such that those portions of the straight line to be followed by any point of the surface to be worked which are contained in the faces of these rubbing portions will always total the same length. Thus, the same duration of contact with the rubbing portions is obtained for all the points of the surface to be worked, which is conductive to uniform working.

The rubbing strips thus defined may have parallel edges, that is to say, be of constant width, whereby uniform feeding is facilitated.

The above and further objects and novel features of the present invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention, reference for this latter purpose being had primarily to the appended claims.

In the drawings, wherein like reference characters refer to like parts throughout the several views,

Fig. l is a plan view of the working face of a tool constructed in accordance with the principles of the invention in which the channels of inlet and discharge are not parallel.

Fig. 2 is a similar plan view of the surface of a tool in which the channels of distribution and discharge are parallel.

Fig. 3 is a plan view of the operating face of a tool having alternating straight and parallel channels of inlet and discharge, seen through the sheet of glass being worked on.

Fig. 4 is a section on the line IV-IV of Fig. 3.

Fig. 5 is a section of the line V-V of Fig. 6 through another modified form of the invention.

F Fig. 6 is a plan view of the working face of the tool of Fig. 7 is a plan view of the working face of a tool every groove of which is provided with a supply orifice and an evacuation orifice.

Fig. 8 is a section along VIVI of Fig. 7, showing the tool in contact with the glass ribbon.

Fig. 9 is a plan view of a further embodiment of runner, such runner having constricted channels.

Referring now to Figs. 3 and 4 a sheet of glass 10 is assumed to be moving in the direction of the arrow, while a polishing tool 11 of rectangular shape is engaged with it; the tool is presumed to be driven with isotropic, periodic translatory motion. The working face of the tool is provided with channels 12 of distribution and chan nels 13 of discharge. The channels are arranged alternately, parallel to the long sides of the tool. Channels 12 are provided with a multiplicity of inlet ports 14 which supply a polishing liquid; these channels are encompassed by lands and thus have closed ends which prevent the escape of the working material by any path except across the faces of the lands. Apparatus, not shown, puts the incoming liquid under sufiicient pressure to force it between the face of the object worked on and the lands regardless of the pressure which may be applied to the tool itself. The channels 13 have open ends which provide for the dischargeof the liquid. These orifices of discharge are indicated at 13.

Fig. 4 shows the vertical construction of the tool and the location of the channels in the system here employed. The tool is constructed of an upper plate 15 and a surfacing body 16 each of which may be composed of any suitable material such as steel and cast iron, steel and felt, or cast iron and a resin or rubber.

In operation, liquid is forced through orifices 14 into channels 12 under sulficient pressure to compel the liquid to enter between the faces of lands 11 and the surface of the glass, from whence some will be discharged outside the tool and some into the channels 13 which, having open ends constituting discharge orifices, permit the evacuation of the detritus at the ends of the tool.

In the form of the invention shown in Fig. 2, the working face of tool 20 is sinusoidal and it is provided with sinusoidal inlet groove 21 and grooves of discharge 22. A continuous land 23 circumscribes groove 21. The working face of the tool is further provided with external lands 24. The motion of the glass is shown by the arrow, the alignment of the lands and grooves being generally transverse to the motion of the glass. In tools of such shape it is advisable that the combined width of all lands on any one line parallel to the motion of the glass shall be substantially equal to the combined width of all lands on any other line parallel thereto. Thus, the combined width of the lands on the line D should approximately equal the combined width of the lands on line D1.

The same principle is used in constructing the polishing tool of Fig. 1, wherein an externally rectangular shape 30 is employed but in which the grooves are not parallel and are not uniform either in shape or size. In this figure external lands 31 are adjacent grooves 3233 of different size and shape which abut a central land 34 which encompasses a supply groove 35 the curvature of which is different from and oppositely directed to the inner boundaries of the grooves 32-33. Nevertheless, this construction gives substantially uniform surfacing because the sum of the widths of all the lands on any line D is substantially equal to the sum of the widths of all the lands on any line D In the form of the invention of Figs. and 6, the grooves 41 of discharge and 40 of admittance are all completely surrounded by lands. The liquid under pressure is forced into groove 40 through inlet 14 and passes outward across the lands 42 to the channels of discharge 41, which are provided with ports of discharge 43 through which the detritus may escape under the pressure existing between the work and the tool, and the pressure imposed frtimowithin on the surfacing material in the supply channe By the principles set forth hereinabove, there is obtained the same duration and degree of working along each line parallel to the direction of motion of the glass.

When the lands are non-uniform or non-parallel it is advisable to make them of complementary shape. All of the channels of supply constitute reservoirs for the aqueous liquid or other surfacing material employed in the operation, and provide uniformity of pressure throughout the length of the channel and consequently uniformity of distribution of the material between the lands and the face of the substance being worked. In most of the figures numerous inlet ports 14 have been illustrated, and are conducive to the maintenance of uni; form supply and pressure in the reservoir, but such numerous orifices are not essential, as illustrated in Figs. 5 and 6.

In the form of the invention of Figs. 7 and 8, the operative face of the tool is provided with grooves 70 parallel to the larger sides of the rectangle and opening at 71 on either smaller edge of the tool alternately. At the closed end of each groove is a channel 72 bringing the polishing liquid from a tank, under pressure not shown.

In the example illustrated in Fig. 7 the pressure of the polishing liquid in the lefthand groove is steadily decreasing from the supply orifice 72 (at top of Fig. 7) to the discharge orifice 71 (at bottom of Fig. 7).

In the next groove the liquid pressure decreases inversely from bottom to top of Fig. 7 so that the working portion between both grooves may be wetted homogeneously with the polishing liquid over its whole length.

The liquid pressure variation along the grooves may be controlled by a proper selection of the number, location and dimension of supply and evacuation orifices.

In. particular the width of the evacuation orifice may be reduced in order to increases the pressure of the polishing liquid in the groove. Eventually, in the case of complete closing of the evacuation orifice of certain grooves, the device works according to the same principle as that shown in Figs. 3 and 4 but with a direct supply into each 8W0 he cross-section of the grooves may be variable, instead of constant as shown in the figures.

The manifold arrangements and, generally speaking, all such arrangements influencing the liquid pressure in the groove afford a means of controlling the penetration of said liquid under the working portions of the tool contacting the surface to be polished.

In'the example of Fig. 7 the grooves are rectilinear and parallel to the larger side of the tool. But, in orden to influence thp liquid pressure along the grooves together. with its time of contact with the glass surface, the grooves may be designed in any convenient manner, e.g. as straight, broken or curved lines.

In Fig. 9 there are shown two similar oppositely. di-

, rected grooves or canals in the working face of the, runner. Each, of such canals 90, has an inlet orifice 91 and. an outlet orifice 92, such orifices being designed to induce flow from the inlet end to the outlet end of the, canal. As a result, stagnation of the glass-polishing sludge between the glass and the. runner is avoided. The. sludge is maintained under reasonably uniform pressure from end to end of the canal, thereby to produce uni.- form feeding of the sludge between the glass and the lands 93, 94, and 95.

As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood] that the invention, is, not limited to the specific embodh, eats.

What is claimed is:

1. Apparatus for polishing glass plates comprising a rectangular polishing tool having a face adapted to. bear. upon the glass plate, alternate. lands and; grooves in said: tool face, said lands and grooves. extending longitudi-. nally of the tool, said grooves being non-intersecting, a fecdingsupply through which the polishing liquid is suplied into said. grooves. nd. f: two. a iacen g ves. are; considered, one at leastis provided with at least one, ori-, lice connected to said feeding supply.

2. The apparatus of claim 1 having means to press the, ee agains t e u e a ing QF W- 3. Apparatus according to claim 1 in which the grooves follow non-parallel paths and the total width of the lands in a direction across the grooves is about the same from end to end of the tool.

4. Apparatus according to claim 1 in which the grooves are non-uniform but the total width of the lands does not vary greatly between the outer ends of the grooves.

5. Apparatus according to claim 1 in which the lands and grooves are approximately rectilinear.

6. Apparatus according to claim 1 in which the lands and grooves are sinusoidal with parallel sides.

7. Apparatus according to claim 1 in which the outlet means includes an open end to a groove.

8. Apparatus according to claim 1 in which the inlet and outlet grooves are reversely curved.

9. Apparatus according to claim 1 in which there are a plurality of inlet grooves.

10. Apparatus according to claim 1 in which there are a plurality of outlet grooves.

11. Apparatus according to claim 1 in which an outlet port is located in the top of a groove.

12. Glass polishing apparatus having means to move a sheet of glass along a predetermined course, a rectangular tool of long bar type on said course, means to impart periodic translatory motion to said tool and to apply the tool to the glass, and means to supply polishing liquid to said tool and to remove it therefrom comprising a source of supply, non-intersecting grooves in the tool extending longitudinally of the tool connected to the source of supply, in such a manner that, if two adjacent grooves are considered, one at least is provided with at least one orifice connected to the said source.

13. Apparatus according to claim 12 in which the total width of the lands in the direction of the motion of the glass is about the same from end to end of the tool.

14. Apparatus for polishing glass plates comprising a polishing tool having a face adapted to bear upon the glass plate, a channel in said tool face having closed ends, port means to introduce the polishing liquid to said channel, and a canal having an escape opening in said tool face beside said channel.

15. Apparatus for polishing glass plates comprising a polishing tool having a face adapted to bear upon the glass plate, a plurality of lands and grooves extending side by side in said tool face, a said groove being encompassed by a land, inlet means for said groove, and outlet means communicating with another groove.

16. A polishing tool comprising a plate having a working surface comprising alternate lands and grooves, means to supply polishing liquid to a plurality of grooves, and if two adjacent grooves are considered, one is provided with an orifice connected to said feeding supply and the other with an outlet for the escape of said liquid.

17. A polishing tool comprising a plate having a working surface comprising alternate lands and grooves, means to supply polishing liquid to a plurality of grooves, the grooves provided with orifices connected to said feeding supply being disposed between two adjacent grooves each provided with at least one outlet for the escape of said liquid.

18. A polishing tool comprising a plate having a working surface comprising alternate lands and grooves, means to supply polishing liquid to a plurality of said grooves, and outlet means permitting the escape of said liquid from at least one groove situated between grooves provided with orifices connected to said feeding supply.

19. A polishing tool comprising a plate having a working surface comprising alternate lands and grooves, means to supply polishing liquid to a first set of a plurality of said grooves, and outlet means permitting the escape of said liquid from a second set of a plurality of grooves, the grooves in the second set being located in alternation with the grooves in the first set.

20. A polishing tool having a face adapted to bear upon the glass plate, alternate lands and grooves in said tool face, means to supply polishing liquid through at least one opening provided in every said groove, and outlet means providing for the escape of said liquid from some said grooves spaced over the area of the tool.

21. A polishing tool having a face adapted to bear upon the glass plate, alternate lands and grooves in said tool face, one end of said grooves being closed and having means supplying polishing liquid, the other end having outlet means permitting the escape of said liquid, closed end and open end alternating with one another.

22. An elongated rectangular tool for polishing a sheet of glass, said tool having on its working face a plurality of spaced longitudinally extending grooves defining a plurality of spaced lands therebetween, said grooves being adapted to conduct a polishing liquid, the grooves and lands being so arranged that of two adjacent grooves at least one has at least one orifice to receive the liquid and the other has at least one orifice for discharging the liquid, whereby the liquid is led in the proper quantity to the working faces of the lands when the tool is presented in operative relationship to the glass.

23. A glass polishing tool as defined in claim 22 adapted for polishing a moving sheet of glass, the tool being adapted to be moved in a circular translatory path with respect to the glass, wherein the grooves in the working face of the tool lie along substantially straight lines and are of sufiicient length to span the entire width of a sheet of glass, the grooves being so disposed that the sum of the widths of the segments of the lands lying along any line at right angles to the length of the tool is substantially a constant.

24. A tool as defined in claim 22 wherein the working face is provided with a plurality of closed grooves, the polishing liquid being admitted to the working face of the tool through orifices provided in each groove and being evacuated from the tool through discharge openings provided in each groove.

25. A tool as defined in claim 22, wherein the grooves are uninterrupted from end to end and the lands between the grooves are uninterrupted from end to end.

26. A tool as defined by claim 22 wherein the working face is provided with a plurality of longitudinally extending grooves, each such groove is provided with orifices for admitting the polishing liquid and orifices for discharging such liquid, and the dimensions and disposition of the feeding and discharge orifices are so chosen that the pressure of the polishing liquid in the grooves is sufficient to cause it to penetrate between the sheet of glass and the lands separating said grooves.

27. A tool as defined by claim 26 wherein each groove has a closed end and an end opening to the atmosphere, and wherein each groove is provided with a liquid-feeding orifice located near its closed end.

28. Apparatus for polishing glass plates comprising a rectangular polishing tool having a face adapted to bear upon the glass plate, alternate uninterrupted lands and grooves in said tool face, said lands and grooves extending longitudinally of the tool, said grooves being non-intersecting, feeding channels through which the polishing liquid is supplied into said grooves, means to force polishing liquid under pressure into the said grooves, and, if two adjacent grooves are considered, one at least is provided with orifices connected to said feeding channels.

29. A polishing tool having a face adapted to bear upon the glass plate, alternate lands and grooves in said tool face, means to supply polishing liquid through at least one opening provided in every said groove, and at least one outlet means providing for the escape of said liquid from every said groove.

References Cited in the file of this patent UNITED STATES PATENTS 1,719,965 Bruhl July 9, 1929 1,892,326 Amsler Dec. 27, 1932 2,019,171 Cassity Oct. 29, l935 

